I mentioned it in the release notes, perhaps not warningly enough.
The migration is to add your github username and token to your git
config, as github recommends for external tools in general:
$ git config --global github.user username
$ git config --global github.token
0123456789yourf0123456789token
http://help.github.com/set-your-user-name-email-and-github-token/
Nathan